This preliminary study examined the effects of full elbow flexion and
full elbow extension on the end-point of active range of motion of sho
ulder flexion and shoulder extension respectively. The end-points were
measured from lateral photographs of the right upper limbs of 30 men
after they flexed and extended their shoulders with their elbows held
in full flexion and full extension. Angular measurements showed that f
ull elbow flexion limited shoulder flexion range of motion and that fu
ll elbow extension limited shoulder extension range of motion. The res
ults indicated that passive muscle insufficiency of active shoulder fl
exion and extension was probably brought about by lengthening the tric
eps brachii and the biceps brachii muscles respectively. Clinicians ar
e encouraged to consider this passive insufficiency when measuring ran
ge of motion of shoulder flexion and extension and when implementing t
herapeutic interventions.